Chapter 10
tibial
Three vasti muscles of quadriceps originate on proximal femur & insert on patellar superior pole -insertion is ultimately on ____ tuberosity via patella tendon
30
with knee flexed __ degrees or > -internal rotation 30 degrees occurs -external rotation 45 degrees occurs
fibula
- lateral -serves as the attachment for knee joint structures -does not articulate with femur or patella -not part of knee joint
Q angle
-Central line of pull for entire quadriceps runs from ASIS to the center of patella -Line of pull of patella tendon runs from center of patella to center of tibial tuberosity -Angle formed by the intersection of these two lines at the patella is the Q angle -Normally, angle will be 15 degrees or less for males & 20 degrees or less in females -Generally, females have higher angles due to a wider pelvis
all 3 vastus
-extension of knee
rectus femoris
-flexion of hip -extension of knee -anterior pelvic rotation
biceps femoris
-flexion of knee -extension of hip -external rotation of hip -external rotation of flexed knee -posterior pelvic rotation
semitendinosus
-flexion of knee -extension of hip -internal rotation of hip -internal rotation of flexed knee -posterior pelvic rotation
semembranosus
-flexion of knee -extension of hip -internal rotation of hip -internal rotation of flexed knee -posterior pelvic rotation (same as tendinosus)
popliteus
-flexion of knee -internal rotation of flexed knee
infrapatellar fat pad
-just posterior to patellar tendon -an insertion point for synovial folds of tissue known as "plica" ---an anatomical variant that may be irritated or inflamed with injuries or overuse of the knee
knee joint
-largest joint in body -very complex -primarily a hinge joint
bursae
-more than 10 ______ in & around knee -some are connected to synovial cavity -they absorb shock or prevent friction
PCL
-not often injured -mechanism of direct contact with an opponent or playing surface
ACL
-one of most common serious injuries to knee -mechanism often involves noncontact rotary forces associated with planting & cutting, hyperextension, or by violent quadriceps contraction which pulls tibia forward on femur
patella
-sesamoid (floating) bone -imbedded in quadriceps & patellar tendon -serves similar to a pulley in improving angle of pull, resulting in greater mechanical advantage in knee extension
synovial cavity
-supplies knee with synovial fluid -lies under patella and between surfaces of tibia & femur -"capsule of the knee"
extension
Anterior - primarily knee _______ Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis
extensors
Femoral nerves innervates the knee _______(quadriceps) rectus femoris vastus medialis vastus intermedius vastus lateralis
pes anserinus
Gracilis, sartorius, & semitendinosus join together distally to form ___ __________
gerdys
Iliotibial tract of tensor fasciae latae inserts on ______ tubercle
femoral
Medial & lateral tibial condyles (medial & lateral tibial plateaus) - receptacles for _______ condyles
flexion
Posterior - primarily knee ______ Biceps femoris Semimembranosus Semitendinosus Sartorius Gracilis Popliteus Gastrocnemius
quadriceps
____ muscle group -extends knee -located in anterior compartment of thigh
rectus femoris
______ ______ (two-joint), vastus medialis, vastus intermedius, vastus lateralis (largest) All attach to patella then to tibial tuberosity via patellar tendon All superficial & palpable except vastus intermedius (under rectus femoris) Strength or power may be indicated by vertical jump test Generally desired to be 25% to 33% stronger than hamstring group
menisci
______ form cushions between bones attached to tibia deepen tibial fossa enhance stability
Strength & endurance
_______ & __________ is essential for maintenance of patellofemoral stability often a problem quads are particularly prone to atrophy when injuries occur may be developed by resisted knee extension activities from a seated position functional weight bearing activities such as step-ups or squats are particularly useful for strengthening & endurance
hamstring
_______ muscle group responsible for knee flexion located in posterior compartment of thigh consists of 3 muscles
Popliteus
________ assist medial hamstrings in knee internal rotation
quadracips
________ muscles - vital in jumping -functions as a decelerator -when decreasing speed to change direction -when coming down from a jump -eccentric contraction during decelerating actions -controls slowing of movements initiated in previous phases of the -sports skill
patellofemoral
_________ joint -arthrodial classification -gliding nature of patella on femoral condyles
ACL
anterior cruciate ligament
flexion
bending or decreasing angle between femur & leg, characterized by heel moving toward buttocks
lateral meniscus
closed C configuration
quadriceps
consists of 4 muscles -rectus femoris -vastus lateralis -vastus intermedius -vastus medialis
tibial
enlarged femoral condyles articulate on enlarged _____ condyles
180
extends to ___ degrees (0 degrees of flexion)
FCL
fibula collateral ligament
LCL
fibular (Lateral collateral ligament) -infrequently injured
140
flexion occurs to about ___ degrees
biceps femoris
hamstring lateral, external rotator
semitendinosus/membranosus
hamstring medial, internal rotator
10
hyperextension of __ degrees or > not uncommon
biceps femoris
inserts primarily on fibula head
external rotation
knee ____ _____ agonists -biceps femoris
flexion
knee _____ Agonists -Biceps Femoris (Long & Short Head) -Semitendinosus -Semimembranosus
internal rotation
knee _____ ______ -Agonists -Semitendinosus -Semimembranosus -Popliteus
extension
knee ______ agonists: -rectus femoris -vastus lateralis -vastus intermedius -vastus medialis
medial meniscus
larger & more open C appearance
TCL
ligament originates on medial aspect of upper medial femoral condyle & inserts on medial tibial surface
tibia
medial and bears most of weight
20-30
neither external or internal rotation will occur unless flexed __-__ degrees or ?
popliteus
originates on lateral aspect of lateral femoral condyle
FCL
originates on lateral femoral condyle very close to popliteus origin & inserts on fibular head
common peroneal
sciatic nerve -______ _______(fibular) division biceps femoris (short head)
extension
straightening or increasing angle between femur & lower leg
MCL
tibial (medial) collateral ligament -maintains medial stability by resisting valgus forces or preventing knee from being abducted -injuries occur commonly, particularly in contact or collision sports -mechanism of teammate or opponent may fall against lateral aspect of knee or leg causing medial opening of knee joint & stress to medial ligamentous structures
TCL
tibial collateral ligament
knee joint proper
tibiofemoral joint -ginglymus
tibial
Sartorius, gracilis, & semitendinosus insert just below the medial condyle on upper anteromedial _____ surface
tibial
Sciatic nerve -______ division ---semitendinosus, semimembranosus, biceps femoris (long head)
posteromedially
Semimembranosus inserts ___________ on medial tibial condyle
knee joint proper
Sometimes referred to as trochoginglymus joint internal & external rotation occur during flexion -Some argue for condyloid classification